Inter-well gas and water flow diagnostics
Inter-well tracer tracking is a proven and efficient technology to map well-to-well communication & heterogeneity. With our 40 unique water tracers and 15 unique gas tracers, Restrack provides the industry’s largest portfolio of field-proven well-to-well gas and water tracers to customers. Restrack’s gas and water tracers have been field-tested in Norwegian oil fields and applied in tracer projects world-wide.
Restrack delivers complete water and gas surveillance services. Restrack personnel have 20 years experience in planning and designing water & gas tracer surveys in oil reservoirs, as well as in tracer operations in the field. Our extensive field operations expertise includes on-shore and off-shore oil fields, from the Arctic to Middle-East deserts & tropical conditions. To guarantee a best possible result, Restrack uses proprietary sample preparation & laboratory methodology in combination with ultra-sensitive laboratory equipment. Restrack’s laboratory facilities with state-of-the-art instrumentation can handle all kinds of water and gas samples.
Near-well oil saturation assessment (SWCTT)
Knowledge of oil saturation is important to assess the potential for producing additional oil and evaluate the effect of enhanced oil recovery (EOR) methodologies. The so-called single-well chemical tracer test (SWCTT) has been used extensively since it’s introduction in the early 1970′s to measure saturations in-situ. The test exploits the time-lag in back-production of injected esters vs. alcohols generated in-situ by partial hydrolysis of ester, and can measure residual oil saturation in a near-well region up to about 10 m from the wellbore. SWCTTs have been used to establish near-well oil saturation in numerous EOR pilots, such as low-salinity pilots.
Restrack’s SWCTT-experience includes the challenging environments represented by offshore rigs on the NCS, with harsh weather conditions, strict security & environmental regulations and complex well and reservoir conditions. Restrack delivers a complete SWCTT-service, including planning, onsite operation, sampling & measurements, and our personnel take full responsibility of the SWCTT-operation, in close collaboration with operator personnel. For interpretation of SWCTT-results we have access to state-of-the-art chemical reaction reservoir simulation tools. In addition we use our in-house ARTSim tracer simulator that enables use of industry standard black-oil simulators for SWCTT-simulation.
Inter-well saturation assessment (PITT)
To quantify remaining oil in between wells, and assess field-scale EOR potential, partitioning inter-well tracer tests (PITTs) have been suggested in oil reservoirs. In a PITT, tracers are injected into injectors and sampled in producers. Then a similar time-lag technique as for SWCTTs is used to quantify the oil saturation in the inter-well reservoir volume. Such tests are well-proven and frequently used to investigate the presence and remediation of non-aqueous phase liquids (NAPLs) in aquifers. Harsh temperature, chemical & microbiological conditions in petroleum reservoirs put severe restrictions on partitioning tracer candidates, and the lack of chemical PITT-tracers with high detection sensitivity, has limited the number of PITTs in oil reservoirs previously. To compensate for this lack, new and stable, oil-water partitioning tracers suitable for use in PITTs in offshore oil reservoirs were recently developed and field tested, allowing measurement of remaining oil saturation in inter-well regions. Restrack can therefore as the only tracer service provider deliver inter-well saturation measurements at normal reservoir conditions.
Our portfolio of six unique proprietary chemical PITT-tracers, together with our water tracers can be used to investigate a range of inter-well regions simultaneously. Our extensive field operations expertise together with proprietary sample preparation & laboratory methodology, and in-house interpretation tools & expertise ensures that a best possible saturation estimate is achieved in the inter-well regions investigated.
Tracers for EOR & specialized operations
Restrack tracer tracking (including IWTT, PITT & SWCTT) can provide essential quantitative information to optimize infill-drilling, polymer blocking, ASP floods and other EOR & IOR operations. In addition, our tracer service has been extended to more specialized operations, such as mud tracing, scale squeeze tracing, CO2-tracing & liquid-holdup tracing in multiphase flow-lines. Restrack personnel have long experience in executing specialized tracer surveys for such cases, with a design tailored to the particular operation.